中文摘要：

以Mg-5Sn-1Si铸态合金为研究对象,分析了合金的相组成及其演化过程。结果表明：Mg-Sn-Si合金中有五种相,分别是基体α-Mg,二元相Mg2Si、Mg2Sn,三元相Mg2（Si,Sn）、Mg2（Sn,Si）;Sn对改善Mg2Si的汉字状结构有关键作用,Sn含量增加会引起Mg2（Si,Sn）或Mg2（Sn,Si）相的数量增加;高温下合金以Mg2Si为母体,生成Si含量较高的Mg2（Si,Sn）复合相,低温下合金以Mg2Sn为母体,生成Sn含量较高的Mg2（Sn,Si）复合相。

英文摘要：

Taking Mg-5Sn-1 Si as-cast alloy as the research object, the phase composition and evolution of Mg-5Sn-1 Si alloy were studied. The results show that Mg5-Sn-5Si alloy includes the following five alloy phases, which are matrix ot-Mg, binary phase Mg2Si and Mg：Sn, ternary phase Mg2（Si,Sn） and Mg2（Sn,Si）. Sn plays a key role in improving the Chinese-script- like Mg2Si phase. With the increase of Sn content, the quantity of Mg2（Si,Sn） or Mg2（Sn,Si） increases. Under the high temperature, the matrix of the alloy is MgaSi, and Mg2 （Si, Sn） composite phase with higher Si content is generated. While the matrix of the alloy is Mg2Sn at low temperature, and the Mg2（Sn,Si） compound phase with higher Sn content is formed.